An advanced dynamic impact extension module, used to protect occupants of vehicles from the adverse effects of extremely rapid deacceleration of a vehicle when the vehicle impacts an end of a concrete barrier wall is disclosed. According to the invention, a barrier wall is provided which has a structural concrete base and a channel portion adaptable to receive low strength reinforced concrete modules. The concrete modules are composed of three layers of crushable material of varying strengths. The first or lowest layer is composed of semi-crushable, higher strength concrete and which is adaptable to secure reinforcement and S-beam connectors. The second layer is lower strength material and the top layer is intermediate strength material. The second and top layer keep an impacting vehicle down and prevent ramping. The modules are arranged linearly beginning at a front end closest to the path of an oncoming vehicle and proceeding toward a back end proximate a roadside obstacle. An impacting vehicle will crush the modules in succeeding fashion according to its impact velocity. The last module in the linear array has triangular steel reinforcement which will cause the impacting vehicle to rise up to avoid the roadside obstacle if the impacting vehicle has sufficient impact force or velocity to crush all the preceding modules. The structural concrete base will coact with the undercarriage of the vehicle in order to bring the vehicle safely to rest before it impacts the roadside obstacle. The height or elevation of the non-crushable concrete base of the barrier will increase in step-wise or sloping fashion so that as a vehicle passes through the barrier, the increased height of the base portions of the barrier base coact with the bottom, or undercarriage, of the vehicle to create friction and drag between the bottom of the vehicle and the base component of the barrier to thereby bring the vehicle to rest before it impacts the end of a concrete barrier wall. ; US